Integrated circuit having frequency dependent noise avoidance

ABSTRACT

A clock source generates a first clock signal for clocking a first clocked module and a rate adapting module produces an operation dependent clock signal from the first clock signal for clocking a second clocked module that is rate dependent. The first clock signal has a rate such that frequency dependent noise components associated with the first clock signal are outside a given frequency range that causes adverse performance in the first clocked module.

CROSS REFERENCE TO RELATED PATENTS

The present U.S. Utility patent application claims priority pursuant to35 U.S.C. §120, as a continuation, to the following U.S. Utility patentapplication which is hereby incorporated herein by reference in itsentirety and made part of the present U.S. Utility patent applicationfor all purposes:

1. U.S. Utility Application Ser. No. 12/796,533, entitled “INTEGRATEDCIRCUIT HAVING FREQUENCY DEPENDENT NOISE AVOIDANCE,” filed Jun. 8, 2010,now U.S. Pat. No. 8,321,716; which claims priority pursuant to 35 U.S.C.§ 120, as a continuation, to the following U.S. Utility PatentApplication, which is incorporated herein by reference in its entiretyand made part of the present U.S. Utility Patent Application for allpurposes:

-   -   A. U.S. Utility application Ser. No. 11/494,147, entitled        “INTEGRATED CIRCUIT HAVING FREQUENCY DEPENDENT NOISE AVOIDANCE,”        filed Jul. 26, 2006, now U.S. Pat. No. 7,793,132.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

NOT APPLICABLE

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

NOT APPLICABLE

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

This invention relates generally to integrated circuits and moreparticularly to noise avoidance within integrated circuits.

2. Description of Related Art

As is known, integrated circuits are used in a wide variety of productsincluding, but certainly not limited to, portable electronic devices,computers, computer networking equipment, home entertainment, automotivecontrols and features, and home appliances. As is also known, integratedcircuits include a plurality of circuits in a very small space toperform one or more fixed or programmable functions.

Many integrated circuits include circuitry that is sensitive to noiseand circuitry that produces noise. For example, a radio frequencyintegrated circuit (RFIC), which may be used in a cellular telephone,wireless local area network (WLAN) interface, broadcast radio receiver,two-way radio, etc., includes a low noise amplifier (LNA) that issusceptible to adverse performance due to noise and also includes ananalog to digital converter and other digital circuitry that producenoise. To prevent the noise from adversely affecting the noise sensitivecircuits (e.g., the LNA) many noise reduction concepts have beendeveloped.

The simplest noise reduction concept is to put noise sensitive circuitson a different IC die than noise producing circuits. While this solvesthe noise sensitivity issue, it does not provide the reduction in formfactor that many products and/or devices are required to have. Anothertechnique is to have the noise sensitive circuits on separate powersupply lines (e.g., positive rail, negative rail, and/or return) andconnected together off-chip. Other techniques include layout management,shielding, etc.

While each of these techniques provides varying levels of noisemanagement, their effectiveness is reduced as the fabrication process ofintegrated circuit shrink and/or as more circuits are placed on the sameintegrated circuit die. Therefore, a need exists for an integratedcircuit that reduces the adverse affects of noise.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to apparatus and methods of operationthat are further described in the following Brief Description of theDrawings, the Detailed Description of the Invention, and the claims.Other features and advantages of the present invention will becomeapparent from the following detailed description of the invention madewith reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a schematic block diagram of an embodiment of an integratedcircuit in accordance with the present invention;

FIG. 2 is a frequency diagram of clock adjusting in accordance with thepresent invention;

FIG. 3 is a schematic block diagram of another embodiment of anintegrated circuit in accordance with the present invention;

FIG. 4 is a frequency diagram of clock adjusting in accordance with thepresent invention;

FIG. 5 is a schematic block diagram of an embodiment of a radiofrequency integrated circuit in accordance with the present invention;

FIG. 6 is a schematic block diagram of an embodiment of a downconversion module in accordance with the present invention;

FIG. 7 is a schematic block diagram of an embodiment of a clock modulein accordance with the present invention; and

FIG. 8 is a schematic block diagram of another embodiment of a clockmodule in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram of an embodiment of an integratedcircuit (IC) 10 that includes a noisy circuit 12, a rate dependentcircuit 14, a noise susceptible circuit 16, a clock module 18, and arate adapting module 20. The circuits 12, 14, and 16 may be any type ofanalog and/or digital circuits that can be implemented on an integratedcircuit including, but not limited to, amplifiers, memory,microprocessors, microcontrollers, baseband processing module, digitalsignal processors, digital logic circuitry, multipliers, adders,arithmetic logic units, analog to digital converters, digital to analogconverters, sensors, impedance matching circuits, input-output circuits,state machines, mixers, and control logic.

The clock module 18, which may be a fractional-N frequency synthesizer,a direct digital frequency synthesizer, a phase locked loop, and/or anycircuit that generates a sinusoidal or square wave repetitive signal ata desired rate, generates a clock signal 22. The noisy circuit 12 isclocked based on the clock signal 22 and when operating causes frequencydependent noise. For instance, the noisy circuit 12 may be clockeddirectly from the clock signal 22, a multiple of the clock signal 22, ora fraction of the clock 22 and causes frequency dependent noise 24 to bepresent in the IC 10. The frequency dependent noise 24, which may beharmonic signal components, spurs, and/or digital noise, may appear onthe substrate of the IC 10, on the positive supply voltage rail, onnegative supply voltage rail, and/or a voltage return rail.

The noise susceptible circuit 16 is susceptible to adverse performancewhen the frequency dependent noise 24 has a component within a givenfrequency range. The given frequency range may be associated with thebandwidth of signals processed by the noise susceptible circuit 16and/or may be a range of operating frequencies of the noise susceptiblecircuit 16. To minimize the adverse performance of the noise susceptiblecircuit 16 due to the frequency dependent noise 24, the rate of theclock signal 22 is set such that components of the frequency dependentnoise 24 associated with the clock signal 22 are outside the givenfrequency range.

The rate dependent circuit 14 requires a specific clock rate (which maybe at a different rate than that of the clock signal 22) to perform oneor more of its functions is clocked based on an operation dependentclock signal 26. The rate adapting module 20, which may be afractional-N frequency synthesizer, a direct digital frequencysynthesizer, a phase locked loop, and/or digital logic circuitry (e.g.,a digital delay line to produce a plurality of delayed clock signalsfrom the clock signal 22, a plurality of inverters to produce aplurality of inverted delayed clock signals, a multiplexer to select oneof the plurality of delayed or inverted delayed clock signals to clock aD flip-flop), is coupled to produce the operation dependent clock signal26 from the clock signal 22.

In one embodiment, the rate adapting module 20 establishes theoperational dependent clock signal 26 by establishing an adjustmentfactor based on the rate dependency of the rate dependent circuit 14 andthe clock signal 22. For example, if the rate dependency of the ratedependent circuit 14 is 100 MHz and the clock signal 22 has a rate of105 MHz, the adjustment factor is 100/105. Having established theadjustment factor, the rate adapting module 20 adjusts the rate of theclock signal 22 based on the adjustment factor to produce the operationdependent clock signal 26.

In one embodiment, the clock module 18 determines whether components ofthe frequency dependent noise 24 are within the given frequency rangefor an initial rate of the clock signal 22. The initial rate of theclock signal 22 may be set at desired rate for the rate dependentcircuit 14, a multiple thereof, and/or a fraction thereof. Note that thedetermining may be done by calculating frequency of the components ofthe frequency dependent noise 24 based on the initial clock rate.Alternatively, the IC 10 may be operated in a test mode at the initialrate of the clock signal 22 and monitoring performance of the noisesusceptible circuit 16. If noise susceptible circuit 16 experiencesminimal adverse affects due to the frequency dependent noise 24 then itcan be assumed that there are no significant components of the frequencydependent noise in the given frequency range.

When the frequency dependent noise components are within the givenfrequency range, the clock module 18 adjusts the rate of the clocksignal 22 such that the frequency dependent noise components associatedwith the clock signal 22 are outside the given frequency range. In oneembodiment, the clock module 18 adjusts the rate of the clock signal 22by calculation. For instance, if the given frequency range is from 960MHz to 1040 MHz, and the initial rate of the clock is 100 MHz, the tenthharmonic of the clock signal 22 is 1000 MHz and is within the givenfrequency range. As such, the clock module 18 determines that a clockrate of 105 MHz produces a ninth harmonic at 945 MHz and a tenthharmonic at 1050 MHz, both of which are outside of the given frequencyrange. Alternatively, the clock module 18 may use a clock rate of 95MHz, which has a tenth harmonic at 950 MHz and an eleventh harmonic at1045 MHz, both of which are outside the given frequency range.

In another embodiment, the clock module 18 may incrementally increase ordecrease the rate of the clock signal 22 during a test mode, where theIC 10 monitors for adverse performance of the noise susceptible circuit14 due to the frequency dependent noise 24. When an acceptable level ofperformance is obtained for a given rate of the clock signal, it is usedfor the clock signal 22. Note that in any of the embodiments of FIGS.1-8, an interpolating and/or anti-aliasing filter may be requiredbetween the noisy circuit and the rate dependent circuit if the noisycircuit and rate dependent circuit are coupled in a series fashion.

FIG. 2 is a frequency diagram of an example of clock adjusting withinthe IC 10 of FIG. 1. In this illustration, the fundamental frequency ofthe operation dependent clock signal 26 includes harmonics 42 that areillustrated using dashed lines. If this rate were used for the clocksignal 22, then there would be a harmonic within the given frequencyrange 40, which might adversely affect the performance of the noisesusceptible circuit. As such, the rate of the clock signal 22 isadjusted such that the fundamental frequency of the clock signal 22 isgreater than or less than (shown as greater than) the rate of theoperation dependent clock signal 26. By adjusting the rate of the clocksignal 22, its harmonic components are also adjusted and can be adjustedto be outside the given frequency range 40. However, the rate dependentcircuit 14 requires a clock based on the operation dependent clocksignal 25, which is derived from the clock signal 22 by the rateadapting module.

FIG. 3 is a schematic block diagram of another embodiment of anintegrated circuit (IC) 50 that includes a noisy circuit 52, a circuit54, a noise susceptible circuit 56, a clock module 58, and a rateadapting module 60. The circuits 52, 54, and 56 may be any type ofanalog and/or digital circuits that can be implemented on an integratedcircuit including, but not limited to, amplifiers, memory,microprocessors, microcontrollers, digital signal processors, basebandprocessing module, digital logic circuitry, multipliers, adders,arithmetic logic units, analog to digital converters, digital to analogconverters, sensors, impedance matching circuits, input-output circuits,state machines, mixers, and control logic.

The clock module 58, which may be a fractional-N frequency synthesizer,a direct digital frequency synthesizer, a phase locked loop, and/or anycircuit that generates a sinusoidal or square wave repetitive signal ata desired rate, generates a clock signal 62. The clock module 18provides the clock signal 62, a multiple thereof, or a fraction thereofto the circuit 54, which requires a specific clock rate to perform oneor more of its functions. Accordingly, the clock module 62 sets the rateof the clock signal 62 to provide the desired clock for the circuit 54.However, if the clock signal 62 were used to clock the noisy circuit 52,frequency dependent noise 64 would be within a given frequency range ofthe noise susceptible circuit 56.

The noise susceptible circuit 56 is susceptible to adverse performancewhen the frequency dependent noise 64 has a component within a givenfrequency range. The given frequency range may be associated with thebandwidth of signals processed by the noise susceptible circuit 56and/or may be a range of operating frequencies of the noise susceptiblecircuit 56. To minimize the adverse performance of the noise susceptiblecircuit 56 due to the frequency dependent noise 64, the rate of theadjusted clock signal 66 is set such that frequency dependent noise 64associated with the adjusted clock signal 66 is outside the givenfrequency range.

To move the frequency dependent noise 64 outside of the given frequencyrange, the rate adapting module 60, which may be a fractional-Nfrequency synthesizer, a direct digital frequency synthesizer, a phaselocked loop, and/or digital logic circuitry (e.g., a digital delay lineto produce a plurality of delayed clock signals from the clock signal62, a plurality of inverters to produce a plurality of inverted delayedclock signals, a multiplexer to select one of the plurality of delayedor inverted delayed clock signals to clock a D flip-flop), is coupled toproduce the adjusted clock signal 66 from the clock signal 62. The rateadapting module 60 provides the adjusted clock signal to the noisycircuit 52.

The noisy circuit 12 is clocked based on the adjusted clock signal 66and when operating causes frequency dependent noise 64. For instance,the noisy circuit 52 may be clocked directly from the adjusted clocksignal 66, a multiple of the adjusted clock signal 66, or a fraction ofthe adjusted clock signal 66 and causes frequency dependent noise 64 tobe present in the IC 10. The frequency dependent noise 64, which may beharmonic signal components, spurs, and/or digital noise, may appear onthe substrate of the IC 50, on the positive supply voltage rail, onnegative supply voltage rail, and/or a voltage return rail.

In one embodiment, the rate adapting module 60 establishes the adjustedclock signal 66 by establishing an adjustment factor based on the givenfrequency range and the clock signal 62. For example, if the givenfrequency range is 960 MHz to 1040 MHz and the rate of the clock signal62 is 100 MHz, then the clock signal has a tenth harmonic at 1000 MHz.The rate adapting module 60 may then determine the adjustment factor as960/1000 or 1040/1000. Having established the adjustment factor, therate adapting module 60 adjusts the rate of the clock signal 62 based onthe adjustment factor to produce the adjusted clock signal 66.

In one embodiment, the rate adapting module 60 determines whethercomponents of the frequency dependent noise 64 are within the givenfrequency range for the clock signal 62. Note that the determining maybe done by calculating frequency of the components of the frequencydependent noise 64 based on the clock rate. Alternatively, the IC 50 maybe operated in a test mode at the rate of the clock signal 22 andmonitoring performance of the noise susceptible circuit 56. If noisesusceptible circuit 56 experiences minimal adverse affects due to thefrequency dependent noise 64 then it can be assumed that there are nosignificant components of the frequency dependent noise in the givenfrequency range.

When the frequency dependent noise components are within the givenfrequency range, the rate adapting module 60 adjusts the rate of theclock signal 62 such that the frequency dependent noise componentsassociated with the adjusted clock signal 66 are outside the givenfrequency range. In one embodiment, the rate adapting module 60 adjuststhe rate of the clock signal 62 by calculation. For instance, if thegiven frequency range is from 960 MHz to 1040 MHz, and the rate of theclock is 100 MHz, the tenth harmonic of the clock signal 22 is 1000 MHzand is within the given frequency range. As such, the rate adaptingmodule 60 determines that a clock rate of 105 MHz produces a ninthharmonic at 945 MHz and a tenth harmonic at 1050 MHz, both of which areoutside of the given frequency range. Alternatively, the rate adaptingmodule 60 may use a clock rate of 95 MHz, which has a tenth harmonic at950 MHz and an eleventh harmonic at 1045 MHz, both of which are outsidethe given frequency range.

In another embodiment, the rate adapting module 60 may incrementallyincrease or decrease the rate of the adjusted clock signal 66 during atest mode, where the IC 50 monitors for adverse performance of the noisesusceptible circuit 54 due to the frequency dependent noise 64. When anacceptable level of performance is obtained for a given rate of theadjusted clock signal, it is used for the adjusted clock signal 66.

FIG. 4 is a frequency diagram of an example of clock adjusting withinthe IC 50 of FIG. 3. In this illustration, the fundamental frequency ofthe clock signal 62 includes harmonics 42 that are illustrated usingdashed lines. If this rate were used to clock the noisy circuit 52, thenthere would be a harmonic within the given frequency range 70, whichmight adversely affect the performance of the noise susceptible circuit56. As such, the rate of the adjusted clock signal 66 is establishedsuch that its fundamental frequency is greater than or less than (shownas less than) the rate of the clock signal 62. By adjusting the rate ofthe adjusted clock signal 66, its harmonic components are also adjustedand can be adjusted to be outside the given frequency range 70.

FIG. 5 is a schematic block diagram of an embodiment of a radiofrequency integrated circuit (RFIC) 80 that includes a low noiseamplifier 82, a down conversion module 84, an analog to digitalconverter module 86, a baseband processing module 88, and a clock module90. The baseband processing module 88 executes digital receiverfunctions that include, but are not limited to, digital intermediatefrequency to baseband conversion, demodulation, demapping, depuncturing,decoding, and/or descrambling. The baseband processing module 88 may beimplemented using a processing device and may have associated memory.Such a processing device may be a microprocessor, micro-controller,digital signal processor, microcomputer, central processing unit, fieldprogrammable gate array, programmable logic device, state machine, logiccircuitry, analog circuitry, digital circuitry, and/or any device thatmanipulates signals (analog and/or digital) based on operationalinstructions. The associated memory may be a single memory device or aplurality of memory devices. Such a memory device may be a read-onlymemory, random access memory, volatile memory, non-volatile memory,static memory, dynamic memory, flash memory, and/or any device thatstores digital information. Note that when the baseband processingmodule 88 implements one or more of its functions via a state machine,analog circuitry, digital circuitry, and/or logic circuitry, theassociated memory storing the corresponding operational instructions isembedded with the circuitry comprising the state machine, analogcircuitry, digital circuitry, and/or logic circuitry.

In operation, the RFIC 80 receives inbound RF signals 92 via an antenna,which were transmitted by a base station, an access point, or anotherwireless communication device. The antenna provides the inbound RFsignals 92 to the low noise amplifier (LNA) 82, which amplifies thesignals 92 to produce an amplified inbound RF signals. The conversionmixing module 84 converts the amplified inbound RF signals into a downconverted signal 96, which may be an intermediate frequency or be atbaseband, based on a local oscillation module 94.

The analog-to-digital converter module 86 converts the down convertedsignal 96 from the analog domain to the digital domain to produce adigital signal 98. The baseband processing module 88 decodes,descrambles, demaps, de-framing, and/or demodulates the digital signal98 to recapture inbound data 100 in accordance with a particularwireless communication standard being implemented by the RFIC 80. Notethat an interpolating and/or anti-aliasing filter may be requiredbetween the ADC module 86 and the baseband processing module 88, wherethe interpolating and/or anti-aliasing filter is clocked at a rate basedon the operation dependent clock signal 104. Further note that eachfunction of the baseband processing module 88 may be clocked from thesame clock, different clocks, or a combination thereof. As such, theoperation dependent clock signal 104 may include one or more clocksignals.

In this embodiment, the clock module 90 generates a first clock signal102 and an operation dependent clock signal 104 such that the rate ofthe first clock signal 102 is set such that frequency dependent noisecomponents associated with the first clock signal 102 are outside afrequency band associated with the inbound RF signal 92 and the rate ofthe operation dependent clock signal 104 is set based on processingspecifications of the digital signal 98. The processing specificationsinclude rates for one or more of framing, demapping, deinterleave, IFFT,decoding, descramble, etc.

The ADC module 86 is clocked by the first clock signal 102 and generatesfrequency dependent noise that may be present in the RFIC 80. Thefrequency dependent noise, which may be harmonic signal components,spurs, and/or digital noise, may appear on the substrate of the IC 80,on the positive supply voltage rail, on negative supply voltage rail,and/or on a voltage return rail. The baseband processing module 88 isclocked by the operation dependent clock 104 to produce the inbound data100 from the digital signal 98. In this manner, the frequency dependentnoise components produced by the digital portion of the ADC module 86 donot adversely interfere with the LNA's 82 amplifying of the inbound RFsignal 92 and yet the baseband processing module 88 is clocked at a raterequired to recover the inbound data 100.

As one of ordinary skill in the art will appreciate, buffering may berequired between noisy circuits and operation rate dependent circuits tocompensate for the different clocking rates. Alternatively, the clockmodule and/or the rate adapting module may include a sample rateconverter to accommodate the differences in clocking rates.

FIG. 6 is a schematic block diagram of an embodiment of a downconversion module 84 that includes a local oscillation module 114, amixing module 110, and a filtering module 112. The mixing module 110includes a pair of mixers and a pair of 90° phase shift modules. Thefirst mixer mixes the amplified inbound RF signal 92 with the localoscillation 94 to produce a first mixed signal. The second mixer mixes a90° phase shifted version of the amplified inbound RF signal 92 with a90° phase shifted version of the local oscillation 94 to produce asecond mixed signal.

The filtering module 112 filters out higher frequency components of thefirst and second mixed signals to produce an in-phase component and aquadrature component of the down converted signal 96. Note that toprocess the in-phase component and a quadrature component of the downconverted signal 96, the ADC module 86 would include two ADCs; one foreach signal component.

FIG. 7 is a schematic block diagram of an embodiment of a clock module90 that includes a clock source 120 and a rate adjust module 122. Theclock source 120, which may be a fractional-N frequency synthesizer, adirect digital frequency synthesizer, a phase locked loop, generates thefirst clock signal 102.

The rate adjust module 122, which may be a fractional-N frequencysynthesizer, a direct digital frequency synthesizer, a phase lockedloop, and/or digital logic circuitry (e.g., a digital delay line toproduce a plurality of delayed clock signals from the clock signal 62, aplurality of inverters to produce a plurality of inverted delayed clocksignals, a multiplexer to select one of the plurality of delayed orinverted delayed clock signals to clock a D flip-flop), generates theoperation dependent clock 104 from the first clock signal 102.

In one embodiment, the clock source 120 determines whether components ofthe frequency dependent noise are within the given frequency range ofthe inbound RF signal. Note that the determining may be done bycalculating frequency of the components of the frequency dependent noisebased on an initial setting of the first clock signal 102 and the givenfrequency range. Alternatively, the RFIC 80 may be operated in a testmode at the initial rate of the first clock signal 102 and monitoringperformance of the LNA 82. If LNA 82 experiences minimal adverse affectsdue to the frequency dependent noise then it can be assumed that thereare no significant components of the frequency dependent noise in thegiven frequency range.

When the frequency dependent noise components are within the givenfrequency range, the clock source 120 adjusts the rate of the firstclock signal 102 such that the frequency dependent noise componentsassociated with the first clock signal 102 are outside the givenfrequency range. In one embodiment, the clock source 120 adjusts therate of the first clock signal 102 by calculation. For instance, if thegiven frequency range is from 960 MHz to 1040 MHz, and the initial rateof the first clock is 100 MHz, the tenth harmonic of the first clocksignal 102 is 1000 MHz and is within the given frequency range. As such,the clock source 120 determines that a clock rate of 105 MHz produces aninth harmonic at 945 MHz and a tenth harmonic at 1050 MHz, both ofwhich are outside of the given frequency range. Alternatively, the clocksource 120 may use a clock rate of 95 MHz, which has a tenth harmonic at950 MHz and an eleventh harmonic at 1045 MHz, both of which are outsidethe given frequency range.

In another embodiment, the clock source 120 may incrementally increaseor decrease the rate of the first clock signal 102 during a test mode,where the RFIC 80 monitors for adverse performance of the LNA 82 due tothe frequency dependent noise. When an acceptable level of performanceis obtained for a given rate of the first clock signal, it is used forthe first clock signal 102.

FIG. 8 is a schematic block diagram of another embodiment of a clockmodule 90 that includes the clock source 120 and a rate adjust module124. The clock source 120, which may be a fractional-N frequencysynthesizer, a direct digital frequency synthesizer, a phase lockedloop, generates the operation dependent clock signal 104.

The rate adjust module 124, which may be a fractional-N frequencysynthesizer, a direct digital frequency synthesizer, a phase lockedloop, and/or digital logic circuitry (e.g., a digital delay line toproduce a plurality of delayed clock signals from the clock signal 62, aplurality of inverters to produce a plurality of inverted delayed clocksignals, a multiplexer to select one of the plurality of delayed orinverted delayed clock signals to clock a D flip-flop), generates thefirst clock signal 102 from the operation dependent clock signal 104.

In one embodiment, the rate adjust module 124 establishes the firstclock signal 102 by establishing an adjustment factor based on the givenfrequency range and the operation dependent clock signal 104. Forexample, if the given frequency range is 960 MHz to 1040 MHz and therate of the operation dependent clock signal 104 is 100 MHz, then theoperation dependent clock signal has a tenth harmonic at 1000 MHz. Therate adjust module 124 may then determine the adjustment factor as960/1000 or 1040/1000. Having established the adjustment factor, therate adjust module 124 adjusts the rate of the operation dependent clocksignal 104 based on the adjustment factor to produce the first clocksignal 102.

In one embodiment, the rate adjust module 124 determines whethercomponents of the frequency dependent noise are within the givenfrequency range. Note that the determining may be done by calculatingfrequency of the components of the frequency dependent noise based onthe clock rate. Alternatively, the RFIC 80 may be operated in a testmode at the rate of the operation dependent clock signal 104 andmonitoring performance of the LNA 82. If LNA 82 experiences minimaladverse affects due to the frequency dependent noise then it can beassumed that there are no significant components of the frequencydependent noise in the given frequency range.

When the frequency dependent noise components are within the givenfrequency range, the rate adjust module 124 adjusts the rate of thefirst clock signal 102 such that the frequency dependent noisecomponents associated with the first clock signal 102 are outside thegiven frequency range. In one embodiment, the rate adjust module 124adjusts the rate of the operation dependent clock signal 104 bycalculation. For instance, if the given frequency range is from 960 MHzto 1040 MHz, and the rate of the operation dependent clock is 100 MHz,the tenth harmonic of the operation dependent clock signal 104 is 1000MHz and is within the given frequency range. As such, the rate adjustmodule 124 determines that a clock rate of 105 MHz produces a ninthharmonic at 945 MHz and a tenth harmonic at 1050 MHz, both of which areoutside of the given frequency range. Alternatively, the rate adjustmodule 124 may use a clock rate of 95 MHz, which has a tenth harmonic at950 MHz and an eleventh harmonic at 1045 MHz, both of which are outsidethe given frequency range.

In another embodiment, the rate adjust module 124 may incrementallyincrease or decrease the rate of the first clock signal 102 during atest mode, where the RFIC 80 monitors for adverse performance of the LNA82 due to the frequency dependent noise. When an acceptable level ofperformance is obtained for a given rate of the first clock signal, itis used for the first clock signal 102.

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “coupled to” and/or “coupling” and/or includes direct couplingbetween items and/or indirect coupling between items via an interveningitem (e.g., an item includes, but is not limited to, a component, anelement, a circuit, and/or a module) where, for indirect coupling, theintervening item does not modify the information of a signal but mayadjust its current level, voltage level, and/or power level. As mayfurther be used herein, inferred coupling (i.e., where one element iscoupled to another element by inference) includes direct and indirectcoupling between two items in the same manner as “coupled to”. As mayeven further be used herein, the term “operable to” indicates that anitem includes one or more of power connections, input(s), output(s),etc., to perform one or more its corresponding functions and may furtherinclude inferred coupling to one or more other items. As may stillfurther be used herein, the term “associated with”, includes directand/or indirect coupling of separate items and/or one item beingembedded within another item. As may be used herein, the term “comparesfavorably”, indicates that a comparison between two or more items,signals, etc., provides a desired relationship. For example, when thedesired relationship is that signal 1 has a greater magnitude thansignal 2, a favorable comparison may be achieved when the magnitude ofsignal 1 is greater than that of signal 2 or when the magnitude ofsignal 2 is less than that of signal 1.

The present invention has also been described above with the aid ofmethod steps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claimed invention.

The present invention has been described above with the aid offunctional building blocks illustrating the performance of certainsignificant functions. The boundaries of these functional buildingblocks have been arbitrarily defined for convenience of description.Alternate boundaries could be defined as long as the certain significantfunctions are appropriately performed. Similarly, flow diagram blocksmay also have been arbitrarily defined herein to illustrate certainsignificant functionality. To the extent used, the flow diagram blockboundaries and sequence could have been defined otherwise and stillperform the certain significant functionality. Such alternatedefinitions of both functional building blocks and flow diagram blocksand sequences are thus within the scope and spirit of the claimedinvention. One of average skill in the art will also recognize that thefunctional building blocks, and other illustrative blocks, modules andcomponents herein, can be implemented as illustrated or by discretecomponents, application specific integrated circuits, processorsexecuting appropriate software and the like or any combination thereof.

What is claimed is:
 1. An apparatus, comprising: a clock source thatgenerates a first clock signal for clocking a first clocked module, thefirst clock signal having a rate such that frequency dependent noisecomponents associated with the first clock signal are outside a givenfrequency range that causes adverse performance in a noise susceptiblemodule; and a rate adapting module that produces an operation dependentclock signal from the first clock signal for clocking a second clockedmodule that is rate dependent; wherein the rate adapting module furtherfunctions to: establish an adjustment factor based on the ratedependency of the second clocked module and the first clock signal; andadjust the rate of the first clock signal based on the adjustment factorto produce the operation dependent clock signal.
 2. The apparatus ofclaim 1, wherein the first clocked module causes the frequency dependentnoise components.
 3. The apparatus of claim 2, further comprising: afilter coupled between the second clocked module and the first clockedmodule, the filter being clocked based on the operation dependent clocksignal.
 4. The apparatus of claim 2, wherein the noise susceptiblemodule is a low noise amplifier, the second clocked module is a basebandprocessing module and the first clocked module is an analog to digitalconversion (ADC) module; and wherein a digital portion of the ADC moduleis clocked based on the first clock signal.
 5. The apparatus of claim 4,wherein the baseband processing module operates to convert an inbounddigital signal into inbound data; and wherein a rate of the operationdependent clock signal is set based on processing specifications of thedigital signal.
 6. The apparatus of claim 1, wherein the rate adaptingmodule comprises at least one of: a fractional-N frequency synthesizer;direct digital frequency synthesizer; a phase locked loop; and digitallogic circuitry.
 7. The apparatus of claim 1, wherein the clock sourcefurther functions to: for an initial rate of the first clock signal,determine whether the frequency dependent noise components are withinthe given frequency range; and when the frequency dependent noisecomponents are within the given frequency range, adjust the rate of thefirst clock signal by calculation such that the frequency dependentnoise components associated with the first clock signal are outside thegiven frequency range.
 8. The apparatus of claim 1, wherein the clocksource further functions to: determine whether the frequency dependentnoise components are within the given frequency range; and when thefrequency dependent noise components are within the given frequencyrange, incrementally adjust a rate of the first clock signal such thatthe frequency dependent noise components associated with the first clocksignal are outside the given frequency range.
 9. The apparatus of claim1, wherein the frequency dependent noise comprises at least one of:harmonic signal components; spurs; and digital noise.
 10. A radiofrequency device, comprising: a clock module that generates a firstclock signal having a rate such that frequency dependent noisecomponents associated with the first clock signal are outside a givenfrequency range, the clock module further producing an operationdependent clock signal from the first clock signal; a low noiseamplifier that is susceptible to adverse performance when the frequencydependent noise components are within the given frequency range; and abaseband processing module having at least one function that is ratedependent and clocked based on the operation dependent clock signal;wherein the clock module further functions to: establish an adjustmentfactor based on the rate dependency of the baseband processing moduleand the first clock signal; and adjust the rate of the first clocksignal based on the adjustment factor to produce the operation dependentclock signal.
 11. The radio frequency device of claim 10, wherein thebaseband processing module operates to convert an inbound digital signalinto inbound data; and wherein a rate of the operation dependent clocksignal is set based on processing specifications of the digital signal.12. The radio frequency device of claim 10, further comprising: ananalog to digital conversion (ADC) module that causes frequencydependent noise, wherein a digital portion of the ADC module is clockedbased on the first clock signal.
 13. The radio frequency device of claim12, further comprising: a filter coupled between the baseband processingmodule and the ADC conversion module, the filter being clocked based onthe operation dependent clock signal.
 14. The radio frequency device ofclaim 10, wherein the clock module further functions to: for an initialrate of the first clock signal, determine whether the frequencydependent noise components are within the given frequency range; andwhen the frequency dependent noise components are within the givenfrequency range, adjust the rate of the first clock signal bycalculation such that the frequency dependent noise componentsassociated with the first clock signal are outside the given frequencyrange.
 15. The radio frequency device of claim 10, wherein the clockmodule further functions to: determine whether the frequency dependentnoise components are within the given frequency range; and when thefrequency dependent noise components are within the given frequencyrange, incrementally adjust a rate of the first clock signal such thatthe frequency dependent noise components associated with the first clocksignal are outside the given frequency range.
 16. The radio frequencydevice of claim 10, wherein the clock module comprises at least one of:a fractional-N frequency synthesizer; direct digital frequencysynthesizer; a phase locked loop; and digital logic circuitry.
 17. Theradio frequency device of claim 10, wherein the frequency dependentnoise comprises at least one of: harmonic signal components; spurs; anddigital noise.
 18. A method for clocking an apparatus, comprising:generating a first clock signal for clocking a first clocked module, thefirst clock signal having a rate such that frequency dependent noisecomponents associated with the first clock signal are outside a givenfrequency range that causes adverse performance in a noise susceptiblemodule; and producing an operation dependent clock signal from the firstclock signal for clocking a second clocked module that is ratedependent; wherein producing the operation dependent clock signalfurther includes: establishing an adjustment factor based on the ratedependency of the second clocked module and the first clock signal; andadjusting the rate of the first clock signal based on the adjustmentfactor to produce the operation dependent clock signal.
 19. The methodof claim 18, wherein generating the first clock signal furthercomprises: determining whether the frequency dependent noise componentsare within the given frequency range; and when the frequency dependentnoise components are within the given frequency range, adjusting therate of the first clock signal such that the frequency dependent noisecomponents associated with the first clock signal are outside the givenfrequency range.
 20. The method of claim 18, wherein generating thefirst clock signal further comprises: determining whether the frequencydependent noise components are within the given frequency range; andwhen the frequency dependent noise components are within the givenfrequency range, incrementally adjusting a rate of the first clocksignal such that the frequency dependent noise components associatedwith the first clock signal are outside the given frequency range.